Aircraft may include multiple line replacement units (LRUs) that are replaceable parts of the aircraft. For example, aircraft brake systems may include a wheel speed sensor or a valve that are relatively easy to replace. The aircraft may further include systems to determine when a LRU has failed. In response to determining that a LRU has failed, a maintenance crew may be notified and the failed part may be replaced. In certain situations, a replacement part may be located at the same location as the aircraft. In such a situation, the aircraft may be grounded for one or more hours while the replacement part is installed. In other situations, the aircraft may be grounded for one or more full day if the replacement part is located at a remote location from the location of the aircraft.